Consolidated Statements Of Changes In Equity - USD ($) $ in Thousands	Total	Total Equity [Member]	Total Shareholders' Equity [Member]	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests [Member]	Redeemable Noncontrolling Interests [Member]	Costa Farms [Member] Redeemable Noncontrolling Interests [Member]	Brahmin [Member] Redeemable Noncontrolling Interests [Member]	Nephila Holdings Limited [Member] Total Equity [Member]	Nephila Holdings Limited [Member] Noncontrolling Interests [Member]
Balance at Dec. 31, 2016		$ 8,467,411	$ 8,460,927	$ 3,368,666	$ 3,526,395	$ 1,565,866	$ 6,484
Balance, shares at Dec. 31, 2016				13,955,000
Balance, redeemable noncontrolling interests at Dec. 31, 2016								$ 73,678
Net income (loss)	$ 400,758	394,374	395,269		395,269	0	(895)	6,384
Other comprehensive income (loss)	779,751	779,705	779,705		0	779,705	0	46
Comprehensive Income (Loss)	1,180,509	1,174,079	1,174,974				(895)	6,430
Issuance of common stock		552	552	$ 552	0	0	0	0
Issuance of common stock, shares				58,000
Repurchase of common stock		(110,838)	(110,838)	$ 0	(110,838)	0	0	0
Repurchase of common stock, shares				(109,000)
Restricted stock awards expensed		15,881	15,881	$ 15,881	0	0	0	0
Restricted stock awards expensed, shares				0
Acquisitions		0	0	$ 0	0	0	0		$ 66,600
Acquisition, shares				0
Adjustment of redeemable noncontrolling interests		(33,738)	(33,738)	$ 0	(33,738)	0	0	33,738
Adjustment of redeemable noncontrolling interests, shares				0
Purchase of noncontrolling interest		(11,285)	(2,955)	$ (2,955)	0	0	(8,330)	(6,179)
Purchase of noncontrolling interest, shares				0
Other		(481)	(655)	$ (310)	(345)	0	174	(7,998)
Other, shares				0
Balance at Dec. 31, 2017		9,501,581	9,504,148	$ 3,381,834	3,776,743	2,345,571	(2,567)
Balance, shares at Dec. 31, 2017				13,904,000
Balance, redeemable noncontrolling interests at Dec. 31, 2017								166,269
Net income (loss)	(130,353)	(129,355)	(128,180)		(128,180)	0	(1,175)	(998)
Other comprehensive income (loss)	(247,630)	(247,590)	(247,590)		0	(247,590)	0	(40)
Comprehensive Income (Loss)	(377,983)	(376,945)	(375,770)				(1,175)	(1,038)
Issuance of common stock		2	2	$ 2	0	0	0	0
Issuance of common stock, shares				32,000
Repurchase of common stock		(54,007)	(54,007)	$ 0	(54,007)	0	0	0
Repurchase of common stock, shares				(48,000)
Restricted stock awards expensed		16,191	16,191	$ 16,191	0	0	0	0
Restricted stock awards expensed, shares				0
Acquisitions		0	0	$ 0	0	0	0	0		$ 19,670	$ 23,392	$ 23,392
Acquisition, shares				0
Adjustment of redeemable noncontrolling interests		(4,828)	(4,828)	$ 0	(4,828)	0	0	4,828
Adjustment of redeemable noncontrolling interests, shares				0
Purchase of noncontrolling interest		(4,986)	(4,986)	$ (4,986)	0	0	0	(7,104)
Purchase of noncontrolling interest, shares				0
Other		(423)	(422)	$ (48)	(374)	0	(1)	(8,563)
Other, shares				0
Balance at Dec. 31, 2018	9,100,302	9,100,302	9,080,653	$ 3,392,993	5,782,310	(94,650)	19,649
Balance, shares at Dec. 31, 2018				13,888,000
Balance, redeemable noncontrolling interests at Dec. 31, 2018	174,062							174,062
Net income (loss)	1,799,462	1,782,646	1,790,466		1,790,466	0	(7,820)	16,816
Other comprehensive income (loss)	303,401	303,422	303,422		0	303,422	0	(21)
Comprehensive Income (Loss)	2,102,863	2,086,068	2,093,888				(7,820)	16,795
Issuance of common stock		43	43	$ 43	0	0	0	0
Issuance of common stock, shares				16,000
Repurchase of common stock	$ (111,600)	(116,307)	(116,307)	$ 0	(116,307)	0	0	0
Repurchase of common stock, shares	(104,719)			(110,000)
Restricted stock awards expensed		16,000	16,000	$ 16,000	0	0	0	0
Restricted stock awards expensed, shares				0
Acquisitions			0	$ 0	0	0		0			$ (8,250)	$ (8,250)
Acquisition, shares				0
Adjustment of redeemable noncontrolling interests		1,105	1,105	$ 0	1,105	0	0	(1,105)
Adjustment of redeemable noncontrolling interests, shares				0
Purchase of noncontrolling interest		(4,219)	(4,219)	$ (4,219)	0	0	0	(4,542)
Purchase of noncontrolling interest, shares				0
Other		3,674	(296)	$ 102	(398)	0	3,970	(7,648)
Other, shares				0
Balance at Dec. 31, 2019	$ 11,078,416	$ 11,078,416	$ 11,070,867	$ 3,404,919	$ 7,457,176	$ 208,772	$ 7,549
Balance, shares at Dec. 31, 2019				13,794,000
Balance, redeemable noncontrolling interests at Dec. 31, 2019	$ 177,562							$ 177,562